Regulator



Patented May 20, 1924.

UNITED STATES 1,494,927 PATENT OFFICE.

FRANK W. MERRILL, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK.

REGULATOR.

Application filed November 25. 1921. Serial No. 517,751.

To all whom it may concern:

Be it known that I, FRANK W. MERRILL,

a citizen of the United States, residing at East Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Regulators, of

which the following is a full, clear, concise, and exact description.

This invention relates to regulators and has particular reference to vibrating contact regulators which are responsive to centrifugal force.

'Heretofore, it has been the custom to construct regulators of this type with point 16 contacts, which vibrated into and out of engagement with each other. In such regulators it has been found necessary to put a change-over switch in the regulating circuit in order that the direction of the current through the regulator might be changed periodically and the building up of the contact surfaces avoided; but even with the current reversing arrangement it was found that the contacts had to be filed frequently. One Hf the objects of the present invention is to o away with the reversing switch and to provide a regulator whose contacts are self-cleaning, and subject to a minimum amount of wear and deterioration, with the result that at accuracy of re ulation is obtained an the maintenance 0 the regulator is small.

Another object of the invention is to provide for an interchanging of, the relative 35 positions of the contacts or the weight whereby the action of centrifugal force may be made to open or to close the contacts of the regulator thus adapting it to various uses. 10 Another object of the invention is to provide a regulator of this type adapted for regulating the speed of an electriemotor, the regulator being so constructed that it may be adjusted while the motor is in operation and a convenient means provided for ascertaining the motor speed to assist in setting the regulator at the desired point.

In one of its embodiments, the regulator comprises a revolving disc having mounted thereon a resilient member to which an arm is attached so that its ends are free to move through a small arc. One end of the mov-' able arm carries an electrical contact and theother end a wei ht so positioned that when the arm is revo ved, centrifugal force moves its Weighted end toward the disc and its other end carrying the electrical contact away from the disc. In moving away from the disc, the revolving contact engages a stationary ring which serves as the cooperating contact of the regulator. The ring is made of metal softer than the rotary vibrating contact to take up the frictional wear between them, and is movable toward and away from the revolving contact for adjusting the length of the arc of vibration so that the regulating point of the regulator may be set as desired.

The regulator is so designed that when mounted upon a rotatingshaft, one end of the said shaft is accessible so that its speed may be measured with a tachometer, and the ring contact of the regulator is so mounted that it may be adjusted while the shaft is in motion, with the result that the setting of the regulator for the desired speed is greatly facilitated.

In the drawings,

Fig. 1 is a vertical cross section of a preferred embodiment of the regulator.

Fig. 2 is a-perspective view of the disc carrying the rotary vibrating contact.

Fig. 3 is a front elevation of the regulator shown in Fig. 1, the end plate being removed.

Fig. 4 is a diagram showing circuit connections for the regulator when used with a shunt wound electric motor.

Referring to the drawings in detail, the improved regulator is-shown as contained within a cup-sha ed housing 1 integral with the casing of a dynamo electric machine 40 (which is of the shunt type as shown in Fig. 4) The armature shaft 3 of the motor projects through the housing, the end of which is closed by a cover 2 of insulating material. A disc 5 of brass or other conducting material is mounted on a bush 37 secured to the shaft 3 and is suitably insulated from the bushing by insulatmg material 9. A threaded washer 10 clamps insulation 9 and disc 5 against a shoulder on bushin 37 so that they rotate therewith. Two flexi le members 11 and 11' (Figs. 2 and 3) are secured at one end to diametrically opposite supports 12 by means of washers 13 and screws 14 and at their adjacent ends to a rigid cross arm 15 by means of rivets 16, the arm 15 having an opening through which the shaft 3 pro ects. 110

I At one end of the rigid arm. 15 and offset from one side thereof is a curved weight 19 which is free to move through a small are about the center line of the flexible members 1'1 and 11' as an axis toward the face of disc 5, when actuated by the centrifugal force due to the rotation of the shaft 3. Contact points 20, mounted'on the opposite end of the rigid member 15, are movable into and out of engagement with the cooperating stationary ring contact 25 accord- I ing as the weight 19 is forced to move toward disc 5' by centrifugal force or away from it by the restoring action of spring members 11 and 11'. A plurality of points 20 are provided in order to increase the area of the contact surface and thus decrease removed from the position shown and inserted therein, in which position they are moved out of engagement-with ring 25 by centrifugal action of the weight 19, as would be desirable, for instance, when the regulator is used with a series wound dynamo electricmachine, as will be hereinafter de scribed. A frame'24 (Fig. 1), which holds a the ring contact 25, is mounted on the inner end of a threaded adjusting screw 4 and maybe moved thereby toward or away from the contacts 20 to vary the arc of vibration of the latter and thus adjust the regulating point of the regulator. seated in a bushing 26 in the cover 2 and is held against rotation by lock nut 27.

Two studs 23 attached to disc 5 are of such .a length as to prevent distortion of the regulator members should the member 25 be moved inwardly too far in adjusting the regulator.

An L-shaped arm 28 .of conducting material has one of its legs secured 'to the bush-' ing 26 and its other {le extending parallel with the lateral wall 0 the housing of the regulator. A carbon brush 29, which .is yielding] mounted within an insulated tubular ousing 30 by means of a spiral s ring 31,- bears upon the horizontal leg of t e arm 28. A threaded cap 33 on the housing 30 is provided with a tip contact 32 to which is soldered one of the conductors-of the circuit. in which the regulator is interposed. A second carbon brush 35 is yieldin ly-mounted within a brush housin 34, -w ich is similarly connected to the ot er lead of the regulating circuit,

the brush 35 being held in .wipmg engagement with the annular flange 6 of the disc 5.

A section 36 of theshaft of thedynamO Adjusting screw 4 is electric machine 40 of smaller diameter than the main shaft 3 extends through the-regu- 'tachometerl This construction permits the regulator to be ,adjustedand its adjustments checked simultaneously, since the tachometer may be held in place while the adjustin screw 4 and the lock nut 27 are manlpulat to obtain the desired adjustment.

The electrical circuit of the regulator when interposed in the field circuit of a shunt wound motor 40, for'controlling the speed thereof, is diagrammatically shown in Fig. 4. Shunt winding 41 of motor 40 has in series therewith a resistance 42, the said W-lIlding being normally energized by a battery or other source of current 43 over a clrcuit extending from the positive pole ofbattery 43, conductors 45 and 46, resistance 42, conductors 47 48, shunt field winding 41, conductors 49 and 50 to the negative pole of battery 43. For motor speeds below normal, the field winding of the motor will be energized over this circuit. In other words, the regulator contacts will be open for motor speeds below normal. However, when. as a result of-an increase of the voltage of the current source a decrease in load or an increase in field temperature or a combination of any of these three causes the motor speed tends, to increase above normal (the value for which the regulator is set), contacts 20 will be -moved into 'engagement with ring contact 25 and resistance 42 will be shortcircuited' Shunt winding 41 will now be energized from the positive pole of battery 43, conductor 45; carbon brush 29, contact arm 28, ring contact 25, contact points 20,'

disc 5, carbon brush 35, conductor 48, shunt field winding 41, conductors 49 and 50, to negative pole of battery 43. An increased current will thus be caused to flow through shunt field 41 and the speed of the motor will be reduced to a. point where contacts 20 will disengage from ring contact 25. In actual practice, the alternate energization of the field winding 41 over the above circuits will be very rapid since contacts 20'are in a continuous state of'vibration moving into and out'of engagement with ring contact 25, several times'per second.

The action of the regulator may be recorresponding to the speed setting. Thus assembled and adjusted the regulator is suit able for connection in parallel with a resistance in series with the line circuit of a series motor or the armature circuit of a shunt motor. When voltage, load and temperature conditions are such that the motor speed is less than normal, the points 20 and ring 25' remain in contact by spring pressure, but when the combination of voltage, load and temperature tend to carry the motor speed above the regulating point, the contacts open by centrifugal force and vibrate across the resistance in such a way as to maintain the motorspeed substantially constant by the intermittent interruption of the series'resistance.

The regulating current in all of the above cases is made to pass from ring contact 25, which is preferably made of nickel, to contacts 20 which are of tungsten, molybdenum, or other suitable material. The electrochemical action between the working contacts causes the formation of a thin coating of nickel on the surface of tungsten contacts 20 giving them a highly polished, smooth surface and modifying their scoring action on the opposing contact. The nickel surface,

on the other hand, is coated with a thin film of nickel oxide. As a result of this film,

.. which is of low electrical resistance, a uniform surface is obtained on the annular contact and the scoring of the hard tungsten contacts is further reduced,

The formation of a thick coating of nickel oxide on the ring contact is prevented by the mechanical interaction of the movable and fixed contacts. Counterweight 21 is made up with a beveled surface 22 which permits the oxide powder brushed off the ring 25 by contacts 20 to be thrown outward into the regulator housing, and thus prevent the possible clogging of the gibratory action of the arm 15 by oxide powder which might otherwise become packed in between contacts 20 and counterweight. 21. Weight 21 is fixedly mounted upon disc member 5. The slight wearon the contact surfaces may be taken u by resetting of adjusting screw 4, during the operation of the regulator, and the powder resulting from .wear of the contacts, which is deposited in the housing 1,

may be removed at any time by the application of compressed air to the housing, suitable orifices (notshown) being provided in the periphery for thispurpose.

The regulator may be used in any device where it is desirable to control an electrical circuit in accordance with the speed of a rotatin member. In addition to its use as as regulator for dynamo electric mac ines, as described above, it may be used to advantage to operate a circuit in which is interposed an electromagnetic valve for controlling a steam engine, an electromagnetic throttle for a gasengine, an ignition circuit for a gas engine, or to regulate the voltage of a variable speed generator. The words translating device in the appended claims are intended to include all such devices in which one form of energy is transformed into another and which are provided with a rotating member by which the regulator may be operated.

What is claimed is:

1. A regulator comprising an annular ring of nickel and a rotating contact point formed of metal of the tungsten group, said contact point movable under the influence of centrifugal force into and out of wiping engagement with said ring,

2. A regulator comprising a ring of nickel and a rotating tungsten contact point, said point being movable under the influence of centrifugal force into and out of vibrating engagement with said ring.

3. A pair of cooperating wiping contact members, one of which is of nickel and the other tungsten coated with nickel.

4. An electrical contacting device comprising a plurality of contacts cooperating to open and close an electrical circuit, said contacts-being of different metals and forming an electrolytic couple whereby metal from one contact is electrodeposited on the other due to current passing between said contacts in the operation of the device.

5. A pair of cooperating electrical contacts, one of which is nickel and the other of which is a metal of such characteristics thatit may be plated with nickel due to electrolytic action upon engagement with said first contact.

6. A pair of cooperating wiping contact surfaces one of which is composed of metal of the tungsten group and the other of which is composed of metal of the nickel group.

7. A regulator comprising a rotatable contact formed of metal of the tungsten group actuated by saidrotatable member and movable in a plurality of planes under the influence of centrifugal force, a fixed ring contact of nickel cooperating with said rotatable contact, and means for adjustingthe relative positions of said fixed and rotating contacts.

8. A regulator comprising an annular member of nickel and a rotating contact point of a metal of the tungsten group covered with nickeLsaid contact point being movable under the'influence of centrifugal force into and out of engagement with the annular member,

9. A regulator .comprising a rotatable disc,

two cross arms mounted at right angles on disc, a rigid member attached to said flexibleme-mber, one end of said rigid member being weighted so as to move relative to said disc under the influence of centrifugal force, electrical contacts on the other end of said rigid member, an annular member adjacent said contacts, and means for adjusting the relative positions of said member and said contacts.

11. A regulator comprising a fixed contact, a rotatable disc, a contact carried by said disc and electrically connected therewith, said contact moved into engagement with said fixed contact by centrifugal force, a terminal electrically connected with'said fixed contact, and a brush engaging the periphery of said rotatable disc. 12. A regulator comprising a rotatable disc, a flexible member mounted at diametrically opposite points on one face of the disc, a'rigid member attached at an "intermediate point to said flexible member, a weighted end for said member free to move under the influence of centrifugal force in a direction parallel to the axis of said rotating disc, a|

' set of contacts controlled by the movement of said weight, an annular member adjacent said contacts, and means for adjusting the speed at which said contacts will come into wiping engagement with said member.

13. A regulator comprising a housing, a rotatable disc within said housing, a pair of lugs carried by said disc at diametrically opposite points adjacent its circumference,

a flexible member upon said lugs, a rigid bar perpendicularly attached to said member having its ends free to move to a limited extent in a direction parallel tothe axis of rotation of the disc, a weight attached to one end of saidbar and offset therefrom, an

electrical contact on the other end ofsaid 14. A regulator having a rotating cont-act and a fixed annular contact moved into enagement with one another by centrifugal orce and means for resetting said regulator whereby said contacts are movedout of' engagement with one another by centrifugalforce.

15. A regulator comprising an annular member of metal and a rotating contact point movable with centrifu a1 force into wiping engagement with sai member, and means for changing the position of said contact point whereby said point is moved out of engagement with said member by centrifugal force. 7

16. A regulator comprising an annular member of metal and a rotating contact point movable with increasing speed into wiping engagement with said ring. and means for changing the position of said contact point whereby said point is moved out of engagement with said ring with increasing speed.

In witness whereof, I hereunto subscribe irgy name this'22nd day of November, A. D.

FRANK W. MERRILL. 

